Linux内核中rbtree的使用

来源：互联网发布：国际标准智商测试软件编辑：程序博客网时间：2024/05/16 17:12

在结构体内嵌struct rb_node

定义根节点struct rb_root

把节点依据key加入红黑树

移除节点

遍历红黑树

#include <linux/module.h>#include <linux/rbtree.h>#include <linux/random.h>#define NODES       20struct test_node {u32 key;struct rb_node rb;u32 val;};static struct rb_root root = RB_ROOT;static struct test_node nodes[NODES];static void insert(struct test_node *node, struct rb_root *root){struct rb_node **new = &root->rb_node, *parent = NULL;u32 key = node->key;while (*new) {parent = *new;if (key < rb_entry(parent, struct test_node, rb)->key) new = &parent->rb_left;elsenew = &parent->rb_right;}rb_link_node(&node->rb, parent, new);rb_insert_color(&node->rb, root);}static inline void erase(struct test_node *node, struct rb_root *root){rb_erase(&node->rb, root);}static void traverse(struct rb_root *root){int i = 0;struct test_node *tn;struct rb_node *node = rb_first(root);printk("%s, %d\n", __func__, __LINE__);while (node) {tn = rb_entry(node, struct test_node, rb);printk("[%2d] tn->key: %u,tn->val: %u\n", i, tn->key,       tn->val);i++;node = rb_next(node);}}static struct test_node *find(u32 key, struct rb_root *root){int found = 0;struct test_node *tn;struct rb_node *node = root->rb_node;while (node) {tn = rb_entry(node, struct test_node, rb);if (key < tn->key) {node = node->rb_left;} else if (key > tn->key) {node = node->rb_right;} else {found = 1;break;}}if (found) {return rb_entry(node, struct test_node, rb);}return NULL;}static void init(void){int i;for (i = 0; i < NODES; i++) {nodes[i].key = random32() % 1024;nodes[i].val = random32() % 1024;}}static void dump_nodes(void){int i;for (i = 0; i < NODES; i++) {printk("nodes[%2d].key: %4u,nodes[%2d].val: %4u\n",       i, nodes[i].key, i, nodes[i].val);}}static int __init test_init(void){int i;struct test_node *tn;init();dump_nodes();for (i = 0; i < NODES; i++) {insert(&nodes[i], &root);}traverse(&root);erase(&nodes[1], &root);traverse(&root);nodes[1].key = 123;insert(&nodes[1], &root);traverse(&root);tn = find(123, &root);if (tn) {printk("found, tn->key: %u,tn->val: %u\n", tn->key, tn->val);erase(tn, &root);traverse(&root);} else {printk("key: 123, not found\n");}tn = find(222, &root);if (tn) {printk("found, tn->key: %u,tn->val: %u\n", tn->key, tn->val);} else {printk("key: 222, not found\n");}return -EAGAIN;}static void __exit test_exit(void){}module_init(test_init);module_exit(test_exit);MODULE_AUTHOR("tony");MODULE_DESCRIPTION("test");MODULE_LICENSE("GPL");MODULE_ALIAS("test");

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